capital investment review

Capital InvestmentReviewColumbia Water & Light.April 15, 2021

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Introduction

This presentation goes over the Distribution level Capital Expenditures including the investments at transmission todistribution substation, medium voltage level investments and medium voltage to low voltage transformers as well asthe priority.

The presentation is organized in the following sections:

• Project prioritization methodology

• Unit costs and Methodology

• Summary of Capital Costs

• Prioritization of Projects and investments: cables, switches and breakers.

• Capacitor Bank investment

• Distribution Transformer investments

• Transmission to Distribution Substation Expansion Investments


Project Prioritization Methodology

In distribution network planning, each project is prioritized according to the level that it addresses performanceviolations in the network so that there is efficient utilization of the investments. Projects that address more severeissues inherently should have higher priority.

The considerations below were used for prioritization of CWL projects:

1. Violation condition: In which operating state the issue is appeared. Normal or emergency conditions. Projectsthat address violations under normal conditions have the highest priority.

2. Total Affected Load : This is measured by the level of overload that would occur on the backup feeder during anoutage on a feeder without the investment. It is proportional to the load that would have to remain disconnectedutil repairs are done on the affected feeder.

3. Number of effected customers : This is determined the Total Affected Loads and the load per customer for eachindividual feeder. It estimates how many customers would be interrupted.

4. Number of Affected feeders : It means that how many feeders are impacted by the same limitation addressed bythe investment.

5. Voltage violation : This is measured by the level of voltage drop that would occur on the existing backup feeder(or affected feeder) during an outage on the affected feeder without the investment.


Project Prioritization Methodology

The project prioritization methodology is described below step by step.

1. Violations in normal condition should be addressed with highest priority.

2. Next issues that appeared during emergency condition are addressed with higher priority to those thataddress high levels of Affected Load.

3. If the Affected load is the same, investments that provide backup to more feeders have higher priority.

4. Capacitor banks for power factor control and voltage profile improvement.


Unit Cost & CapEx Methodology

Cables Unit Cost [$/mile]Underground feeder, 3# 500 CU $1.521.492

Capacitor Banks Unit Cost [$]300 kVAr $4.073600 kVAr $8.146900 kVAr $12.2201200 kVAr $16.293

Switching Equipments Unit Cost [$]Breaker - HV $673.272Breaker - MV $149.085Switch 600 Amp Class $80.250

Distribution Transformers Unit Cost [$/kVA]Transformer $233

Power Transformers Unit Cost [$/MVA]Transformer $29.438

The unit costs as shown to the right were selected for CWL capitalexpenditure calculations. These costs are typical for the Midwestcontinental US. However, they are subject to review.

The assumptions for unit costs;

• For new feeders/sections, 500CU underground cable isconsidered according to planning criteria. Unit cost for cables isa total which includes cable, trenching and substructure costs.

• For switching equipment, HV and MV breakers areconsidered for new power transformers in substationexpansions. Additionally, MV breaker is considered for newfeeder connections to the substation. Switches are widely usedalong distribution feeders.

• For capacitor banks, 300 kVAr and multiples are consideredaccording to planning criteria. Unit cost for capacitor banksincludes all hardware costs for connection.


Unit Cost & CapEx Methodology

Cables Unit Cost [$/mile]Underground feeder, 3# 500 CU $1.521.492

Capacitor Banks Unit Cost [$]300 kVAr $4.073600 kVAr $8.146900 kVAr $12.2201200 kVAr $16.293

Switching Equipments Unit Cost [$]Breaker - HV $673.272Breaker - MV $149.085Switch 600 Amp Class $80.250

Distribution Transformers Unit Cost [$/kVA]Transformer $233

Power Transformers Unit Cost [$/MVA]Transformer $29.438

The assumptions for unit costs (cont.) ;

• For both power and distribution transformers, Unit costincludes all hardware costs for connection.

• Pad-mounted Switches considered .

Typical cost calculation approach;

• For new sections Cable + 1 Switch Cost

• For new feeders Cable + 1 Switch + 1 Breaker Cost

This approach is general but was finetuned by project basis.

• For Substation Expansion Power Trf + 1 HV Breaker + 1MV Breaker


CWL - Capital Expenditure

The table below shows CWL capital expenditure budget for distribution and transmission/distribution substations.Distribution level budget are based on comprehensive analysis and includes cost of underground cable, switchingequipment, distribution transformer and capacitor banks.

Transmission level budget includes the power transformer and one HV and MV breaker costs.

The investments with priority are shown in the next slide.

2025 2030 2040 Total$36.869.668 $2.933.495 $6.555.517 $46.358.680

Underground Cable $18.580.462 - - $18.580.462Breaker&Switch $3.473.932 - $80.250 $3.554.182Distribution Transformer $14.456.835 $2.892.763 $6.340.852 $23.690.450Capacitor Bank $358.440 $40.732 $134.415 $533.587

$4.610.134 $0 $0 $4.610.134Power Transformer $2.143.063 - - $2.143.063Breaker $2.467.071 - - $2.467.071

$41.479.802 $2.933.495 $6.555.517 $50.968.814

CWL Investments

Total

Distribution Level

Transmission Level

Cost [$]


Distribution LevelProject Prioritization

Priority Project NameViolation Condition

Total Effected Load

Number of Effected

Customers

Number of Effected Feeders

Voltage Violation

1 Project 15 Normal 1,47 187 1 -2 Project 11 Normal 0,00 0 3 98,33 Project 20 Emergency 8,12 2404 3 96,34 Project 8 Emergency 7,48 1724 7 97,95 Project 19 Emergency 4,20 959 2 -6 Project 12 Emergency 3,62 76 1 -7 Project 16 Emergency 2,95 375 2 -8 Project 7 Emergency 2,63 538 2 -9 Project 9 Emergency 2,11 723 2 -10 Project 13 Emergency 1,91 436 1 -11 Project 4 Emergency 1,87 95 2 98,112 Project 17 Emergency 1,83 559 3 -13 Project 6 Emergency 1,61 203 1 98,814 Project 2 Emergency 1,01 2 1 -15 Project 1 Emergency 1,01 39 2 -16 Project 18 Emergency 0,93 8 1 -17 Project 14 Emergency 0,55 145 1 -18 Project 5 Emergency 0,54 137 1 -19 Project 10 Emergency 0,29 55 1 98,520 Project 3 Emergency 0,00 0 1 98,8

Distribution investment weregrouped in projects as discussedearlier and summarized in thesupporting slides at the end of thispresentation.

The table to the right shows thepriority of these projects consideringthe criteria presented before.

The first two projects 15 & 11address issues on the system intact.Project 15 addresses overloads on asection of feeder GS231 out ofGrindstone and 11 voltage drops onPC221 out of Perche Creek.

Note that the Affected Load is thecentral factor for the prioritization.


Distribution LevelUnderground Cables

The total investment in underground cables with priority isshown in the table to the right that shows the line length andcost for each project.

We note that Project 11has the highest cost and high priority.This project was discussed during our last presentation and itincludes the new feeder out of Perche Creek that will addressvoltage and loading issues and provides a second source tothe residential area to the south.

The next project in cost is Project 17 that addresses andoverload during emergency condition on feeder RH214 as ittries to provide backup to RH 224 both out of Rebel Hill.

As mentioned before, 500 CU is used for the newinvestments as these are mainlines and in accordance withthe planning criteria.

Priority Project NameTotal Line

Length [mi]Line Cost [$]

1 Project 15 0,065 $98.8972 Project 11 4,831 $7.350.3283 Project 20 1,389 $2.113.3534 Project 8 0,079 $120.1985 Project 19 0,799 $1.215.6726 Project 12 0,005 $7.6077 Project 16 0,391 $594.9038 Project 7 0,003 $4.5649 Project 9 0,002 $3.04310 Project 13 0,314 $477.74911 Project 4 1,132 $1.722.32912 Project 17 2,188 $3.329.02513 Project 6 0,197 $299.73414 Project 2 0,012 $18.25815 Project 1 0,227 $345.37916 Project 18 0,06 $91.29017 Project 14 0,007 $10.65018 Project 5 0,509 $774.43919 Project 10 - -20 Project 3 0,002 $3.043

Total 12,212 $18.580.462


Distribution LevelUnderground Cables

The investment in cables are largely for new feeders butthere are investments in replacing the cables by a largercross section cable (reconductoring).

The table to the left provides the split of these costs and thetables below shows the split by substation and feeders.

We note as indicated earlier that all new investments arewith cables 500CU

The new sections are split into new sections along existingfeeder and new feeders.

Substation Feeder Name Type Length [mi]Bolstad BD231_ST 500 CU 1,144Perche Creek PC231_ST 500 CU 0,079Perche Creek PC232_ST 500 CU 2,548Rebel Hill RH231_ST 500 CU 1,349Rebel Hill RH232_ST 500 CU 2,188

Total 7,308

New SectionsSubstation Feeder Name Type Length [mi]Bolstad BD213 500 CU 0,002Bolstad BD223 500 CU 0,227Grindstone GS211 500 CU 0,391Grindstone GS232 500 CU 0,007Harmony BranHB231 500 CU 2,285Rebel Hill RH221 500 CU 0,06Rebel Hill RH223 500 CU 0,799

Total 3,771

New SectionsSubstation Feeder Name Type Length [mi]Blue Ridge BR212 500 CU 0,213Grindstone GS231 500 CU 0,065Harmony Branch HB233 500 CU 0,005Hinkson Creek HC231 500 CU 0,314Power Plant PP212 500 CU 0,296Power Plant PP221 500 CU 0,003Power Plant PP223 500 CU 0,197Rebel Hill RH231_ST 500 CU 0,040

Total 1,133

Reconductoring

FeederTotal Line

Length [mi]Line Cost [$]

New Feeder 11,079 $16.856.611Reconductor 1,133 $1.723.851Total 12,212 $18.580.462

New feedersNew Sections on existing feeders Cable replacement (reconductoring)


Distribution LevelBreaker and Switches

There is a total of 5 new feeders proposedas presented earlier and detailed below thus5 breakers are costed• Project 4 out of Bolstad (BD231_ST),• Project 8 and 11 out of Perche Creek

(PC231_ST and PC_232_ST),• Project 17 and 20 Out of Rebel Hill

(RH232_ST and RH231_ST). With respect of the switches, there are 34

new switches identified most of them associated with specific projects as shown to the left. However, there are 7 new switches that were located to sectionalize the system and allow more efficient transfer of load between feeders.

Number of Breaker

Number of Switch

Breaker Cost [$]

Switch Cost [$]

Total Cost in 2025 [$]

Number of Breaker

Number of Switch

Breaker Cost [$]

Switch Cost [$]

Total Cost in 2025 [$]

Total Cost

1 Project 15 0 0 $0 $0 $0 0 0 $0 $0 $02 Project 11 1 4 $149.085 $321.001 $470.086 0 0 $0 $0 $03 Project 20 1 3 $149.085 $240.751 $389.836 0 0 $0 $0 $04 Project 8 1 5 $149.085 $401.251 $550.336 0 0 $0 $0 $05 Project 19 0 3 $0 $240.751 $240.751 0 0 $0 $0 $06 Project 12 0 0 $0 $0 $0 0 0 $0 $0 $07 Project 16 0 0 $0 $0 $0 0 0 $0 $0 $08 Project 7 0 0 $0 $0 $0 0 0 $0 $0 $09 Project 9 0 1 $0 $80.250 $80.250 0 0 $0 $0 $010 Project 13 0 0 $0 $0 $0 0 0 $0 $0 $011 Project 4 1 1 $149.085 $80.250 $229.335 0 0 $0 $0 $012 Project 17 1 2 $149.085 $160.500 $309.585 0 0 $0 $0 $013 Project 6 0 1 $0 $80.250 $80.250 0 0 $0 $0 $014 Project 2 0 0 $0 $0 $0 0 0 $0 $0 $015 Project 1 0 3 $0 $240.751 $240.751 0 0 $0 $0 $016 Project 18 0 1 $0 $80.250 $80.250 0 0 $0 $0 $017 Project 14 0 0 $0 $0 $0 0 0 $0 $0 $018 Project 5 0 0 $0 $0 $0 0 0 $0 $0 $019 Project 10 0 1 $0 $80.250 $80.250 0 0 $0 $0 $020 Project 3 0 2 $0 $160.500 $160.500 0 0 $0 $0 $021 Sectionalizing 0 7 $0 $561.751 $561.751 0 1 $0 $80.250 $80.250

Total 5 34 $745.426 $2.728.506 $3.473.932 0 1 $0 $80.250 $80.250 $3.554.182

Priority Project Name

2025 2040

Equipment Number Cost [$] Number Cost [$] Number Cost [$] Number Cost [$]Switch 34 $2.728.506 - - 1 $80.250 35 $2.808.756Breaker 5 $745.426 - - - - 5 $745.426Total 39 $3.473.932 - - 1 $80.250 40 $3.554.182

2025 2030 2040 Total


Distribution LevelDistribution Transformers and capacitors

The spatial load forecast provided indication where theload was likely to grow and based on this the need fornew distribution transformers was assed. The table tothe right shows this estimation and the expected costsby year.

Capacitor banks were added to the network as detailedin the table below for voltage support and power factorcorrection. The cost is provided in the table to the right.

Dist. Transformers 2025 2030 2040 TotalTotal Installed Power [MVA] 62,11 12,43 27,24 101,79Total Cost [$] $14.456.835 $2.892.763 $6.340.852 $23.690.450

300 kVAr 600 kVAr 900 kVAr 1200 kVAr 300 kVAr 600 kVAr 900 kVAr 1200 kVAr 300 kVAr 600 kVAr 900 kVAr 1200 kVArBlue Ridge 0 0 0 1 0 0 0 0 1 0 0 0Bolstad 1 2 2 1 1 2 0 0 2 4 2 0Grindstone 0 3 2 1 0 0 1 0 0 0 0 1Harmony Branch 0 1 1 0 0 0 0 0 0 0 0 0Hinkson Creek 2 0 1 0 0 0 0 0 1 0 0 1Perche Creek 1 0 0 2 0 0 0 0 0 0 0 0Power Plant 1 2 3 0 1 0 0 0 1 0 1 0Rebel Hill 3 3 1 2 1 0 0 0 3 0 0 0Total 8 11 10 7 3 2 1 0 8 4 3 2

Substation List2025 2030 2040

Capacitor Banks 2025 2030 2040 TotalNumber of Capacitor Banks 36 6 17 59Total Reactive Power [MVAr] 26,4 3 9,9 39,3Total Cost [$] $358.440 $40.732 $134.415 $533.587


Transmission LevelSubstation Transformer Expansion

From the spatial load forecast assessment and the expectation of load to be served by each substation after the recommended load transfer, three substations: Bolstad, Rebel Hill and Perche Creek were identified as requiring increases in

Substation VoltagePower

Transformer [MVA]

HV Breaker MV Breaker Trf CostHV

Breaker Cost

MV Breaker

Cost

Total Cost [$]

Bolstad 69/13,8 kV 22,4 1 1 $659.404 $673.272 $149.085 $1.481.761Rebel Hill 161/13,8 kV 28 1 1 $824.255 $673.272 $149.085 $1.646.612Perche Creek 69/13,8 kV 22,4 1 1 $659.404 $673.272 $149.085 $1.481.761

Total $2.143.063 $2.019.815 $447.255 $4.610.134

2025

NAMELOAD (2020)

Capacitors Installed in new area

1200 kVAr Capacitors

needed

Transformers Load

Transformers Load

Coincident Load 2025

(FP=1)

Coincidence Factor

Peak Load 2025

(FP=1)

PRESENT CAPACITY

FUTURE CAPACITY

FUTURE LOAD/CAP.

N-1Nº TRX

2020Nº TRX

2025

[MVA] [MVAR] [MW] [MVAr] [MVA] [MVA] [MVA] [MVA] [%] [%]Bolstad 14.28 12.90 3 16.20 9.49 16.20 1.6961 27.47 44.8 67.2 41% 61% 2 3Blue Ridge 23.84 8.70 0 18.94 6.81 18.94 1.0000 18.94 44.8 44.8 42% 85% 2 2Grindstone 34.90 15.00 4 36.73 16.31 36.73 1.1956 43.91 67.2 67.2 65% 98% 3 3Harmony Branch 40.55 29.70 0 40.15 17.36 40.15 1.0000 40.15 67.2 67.2 60% 90% 3 3Hinkson Creek 45.15 20.10 0 44.45 18.29 44.45 1.0004 44.47 67.2 67.2 66% 99% 3 3Perche Creek 35.08 13.50 0 35.01 10.82 35.01 1.0285 36.01 44.8 67.2 54% 80% 2 3Power Plant 47.77 18.30 3 40.95 20.29 40.95 1.0749 44.02 67.2 67.2 66% 98% 3 3Rebel Hill 31.72 19.05 2 43.79 20.64 43.79 1.0000 43.79 56.0 84.0 52% 78% 2 3

The transformation capacity

The distribution analysis work confirmed this need, and the table to the right shows the expected investments by substation.

Note that these assumes that there is space available and minimum investments are required for site preparation.

Backup slidesProject overview


ProjectsProject 1

BD223BD212

BR221 NewConnection

Element Name Type Name l [mi] YearL142160_ST 500_Cu 0,227 2025


ProjectsProject 2

BD211

BD231_ST

NewConnection



ProjectsProject 3

NewConnection

BD213

BD223



ProjectsProject 4

BD231_ST

NewFeeder

Element Name Type Name l [mi] YearBD231_ST 500_Cu 0,008 2025L142219_ST 500_Cu 0,615 2025L142221_ST 500_Cu 0,509 2025

Bolstad


ProjectsProject 5

BR212

PP233

PP212

Reconductor

Element Name Type Name l [mi] YearL142184_ST 500_Cu 0,213 2025L142185_ST 500_Cu 0,228 2025L142186_ST 500_Cu 0,068 2025


ProjectsProject 6

PP233

PP214

Reconductor

ConnectionChange

Element Name Type Name l [mi] YearL142192_ST 500_Cu 0,002 2025L142193_ST 500_Cu 0,001 2025L142194_ST 500_Cu 0,002 2025L142195_ST 500_Cu 0,192 2025


ProjectsProject 7

PP221 Reconductor

Element Name Type Name l [mi] YearL142200_ST 500_Cu 0,001 2025L142201_ST 500_Cu 0,002 2025


ProjectsProject 8

PC223

New Feeder

PC231_ST

Element Name Type Name l [mi] YearL142205_ST 500_Cu 0,07 2025PC231_ST 500_Cu 0,009 2025

Perche Creek


ProjectsProject 9

HB231

NewConnection



ProjectsProject 10

NewCapacitor

Element Name Type Name Qn [MVAr] YearSHC142217_LT Capacitor 1,5 2040


ProjectsProject 11

NewConnection

New Feeder

Element Name Type Name l [mi] YearL142214_ST 500_Cu 2,284 2025L142215_ST 500_Cu 2,502 2025PC232_ST 500_Cu 0,009 2025L142226_ST 500_Cu 0,036 2025

Perche Creek


ProjectsProject 12

Reconductor

HB233



ProjectsProject 13

Element Name Type Name l [mi] YearL142091_ST 500_Cu 0,039 2025L142092_ST 500_Cu 0,004 2025L142093_ST 500_Cu 0,003 2025L142096_ST 500_Cu 0,059 2025L142097_ST 500_Cu 0,003 2025L142098_ST 500_Cu 0,002 2025L142099_ST 500_Cu 0,026 2025L142100_ST 500_Cu 0,003 2025L142101_ST 500_Cu 0,002 2025L142102_ST 500_Cu 0,006 2025L142103_ST 500_Cu 0,002 2025L142104_ST 500_Cu 0,002 2025L142105_ST 500_Cu 0,156 2025L142106_ST 500_Cu 0,001 2025L142107_ST 500_Cu 0,001 2025L142108_ST 500_Cu 0,004 2025L142109_ST 500_Cu 0,001 2025

HC231

Reconductor

HC211

GS211


ProjectsProject 14

NewConnection

GS213

GS232



ProjectsProject 15

GS231

Reconductor


Grindstone


ProjectsProject 16

GS231

GS211

NewConnection

Element Name Type Name l [mi] YearGS211_ST 500_Cu 0,065 2025L142115_ST 500_Cu 0,326 2025

GS211

NewConnection

Grindstone


ProjectsProject 17

RH224

Rh214

RH232_ST

New Feeder

Element Name Type Name l [mi] YearL142156_ST 500_Cu 2,161 2025L142157_ST 500_Cu 0,01 2025RH232_ST 500_Cu 0,017 2025

Rebel Hill


ProjectsProject 18

RH221

NewConnection


Rebel Hill


ProjectsProject 19

NewConnection

RH223

RH231



ProjectsProject 20

New Feeder

RH231_ST

Element Name Type Name l [mi] YearL142127_ST 500_Cu 1,334 2025L142133_ST 500_Cu 0,003 2025L142134_ST 500_Cu 0,037 2025RH231_ST 500_Cu 0,015 2025

Rebel Hill


Siemens PTI – Master Plan Primary Points of Contact for CWL

Nelson BacalaoSenior Consulting ManagerPhone +1 (713) [email protected]

Ismail SahinConsultantPhone +90 (530) [email protected]

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